The invention relates to a device for releasing a securing screw for a unit in a housing, in particular a pinion in a steering gear of a motor vehicle.
Known positional securings are implemented via bolted connections, e.g. steel screws, having a metric thread. The screw lock is achieved in a force-locking manner via a tightening torque, via caulking, or via an adhesive joint. In known securings, a bearing, for example, is fixed with the aid of a zinc die-cast adjusting screw, for example, which is fixed in the position thereof according to a defined tightening torque with the aid of a caulking process.
The use of materials having different coefficients of thermal expansion poses a problem, however, whereby the securing effect diminishes over the service life and/or play may even result. The setting properties of the material of the adjusting screw relative to the housing material also negatively affect securing or fixation. It is also disadvantageous that the adjusting screw must be fixed in the position thereof in the housing in a separate working cycle. Given that the preload of the adjusting screw may decrease to zero over the course of the service life, it is possible for play to form between the unit to be secured, e.g. a fixed bearing, and the adjusting screw or the housing. The result thereof is frictional wear, and acoustic problems can occur.
A thread sealing agent is often used for sealing against external media, which also increases the complexity of the manufacturing and/or assembly process.
The problem addressed by the present invention is therefore that of creating a low-cost and easily assembled device for securing a unit, wherein play-free fixation should be given throughout the service life and the securing can be released, if necessary.